Citing 'extreme concern,' Iowa State University destroys anthrax

AMES, Iowa (CNN) --Iowa State University destroyed its anthrax sample last month because of concerns over security in the wake of tainted letters that have apparently infected 17 people.

The sample, a strain that dated to the 1920s, was destroyed October 11 after "extensive consultation with proper officials," including the FBI, a university spokesman told CNN Friday.

University officials also consulted with the Centers for Disease Control and Prevention on whether it was a one-of-a-kind sample, the spokesman said. Assured it was not, the university decided to destroy it because of the "extreme concern over the whole anthrax issue," the spokesman said.

It was destroyed in an autoclave, a device similar to a sophisticated pressure cooker, and was then incinerated.

When the anthrax scare began last month, the governor of Iowa increased security at state labs that had anthrax, according to the university spokesman. While a University of Iowa lab had the National Guard at its lab, Iowa State University had one state trooper, the spokesman said.

The University of Iowa has no plans to destroy its sample, which the lab's director described as a "vaccine strain," that is far less virulent than others.

"It's not really dangerous to a human being," said Dr. Mary Gilchrist, director of the lab in Iowa City. Gilchrist said security had been beefed up at the lab, including the temporary use of National Guard troops and a new lock system.